Cell phones are commonly used as positioning devices for home or small-range applications. The cell phones mainly relate to terminal cell phone modules, wireless data communication modules, and global positioning modules (i.e. GPS). When a terminal cell phone module is connected to a mobile communication network, and the wireless data communication module is connected to the Internet, the global positioning module can receive positioning signals from satellites, thereby allowing the cell phone to transmit a position data to a control center through the mobile communication network or the Internet for operation.
However, even though cell phones can receive positioning signals from satellites for positioning, signals from satellites are easily affected by weather and terrains. When a user is inside a building or other locations which blocks signals, the GPS is particularly inaccurate. Moreover, mobile communication network is restricted to locations where base stations are set by telecommunication companies, and the Internet is limited to locations with access thereto. Therefore, when a user intends to use a cell phone for positioning in a home or office, restrictions often affect the positioning and create inconvenience.